The purpose of this proposal is to develop radioimmunoassays for two major lipase enzymes released into human plasma by intravenous heparin injection. These are lipoprotein lipase which is present in most extrahepatic tissues and the postheparin hepatic triglyceride lipase (H-TGL) which is thought to be almost exclusively the product of the liver. Correlations of enzyme activity with enzyme mass will be made in postheparin plasma samples as well as human biopsy specimens of adipose tissues and muscle. Correlations of mass and activity in liver will utilize the cynomolgous monkey from which the hepatic triglyceride lipase has been shown to cross react with antisera to the human enzyme. Isolated adipocyte studies will be undertaken to demonstrate the hypothetical presence of an inactive pool of LPL in adipose tissue whose release is stimulated by heparin. These studies will involve the use of inhibitors of protein synthesis as well as inhibitors of energy transfer. Primary cultures of monkey liver cells will be attempted to provide a system for study of H-TGL synthesis and secretion using the radioimmunoassay developed above.